Trucks having front engines and rear wheel drive require long drive shafts to transmit torque from the engine to the rear wheels. When a drive shaft is longer than a certain length, design rules dictate that it be supported at its mid section or at multiple locations to avoid "whipping" in the manner of a taut jump rope. The shaft is segmented into segments joined by universal joints, and the end of at least one of the segments is supported by a beating attached to the truck frame adjacent the universal joint.
Typical truck frames are shaped like ladders, and the shaft support bearing is mounted to the cross members of the frame. Often, trucks must be built to customers' specifications, which may include different frame lengths. A different frame length may dictate a different number of drive shaft segments, different shaft lengths, and support bearing locations to meet design rules. This requires that the frame cross members be relocated to accommodate the bearing requirements. However, many other components are normally attached to the frame rails between the cross members (e.g. air tanks, fuel tanks, brake components, etc.) When the drive shaft beating must be moved, some or all of the components must be relocated, requiring extensive engineering time, and potentially compromising other design rules when design conflicts arise.
The disclosed apparatus overcomes these disadvantages by providing a truck frame with elongated frame rails, a plurality of cross members each spanning between and connected to each of the rails, a first and second of the cross members being spaced apart to define a gap. An elongated bridge having a first and second end is connected at its first end to an intermediate point on the first cross member, and at its second end to an intermediate point on the second cross member. The bridge may include multiple mounting locations so that the bearing may be remounted within a selected range of positions along the bridge.